Beginners Guide to Connecting Your RC Plane Electronic Parts

I'm into building RC planes. One problem I had was that couldn't find a guide to the basics of connecting all the electronics parts together (on instructables). Hopefully this I'ble will help you get started with your RC plane.

My goal is to give you a general idea of what each component is show you how to hook them up.

Biolethal made a very good instructable on a COMPLETE guide to RC electronics so for more detail on each part please read his i'ble. While he thoroughly explains each component, he doesn't explain how to hook it all up. That is the goal of this i'ble to explain how to connect everything.

Also another good place to get started with RC is http://makezine.com/makerhangar/, but I don't recommend making the plane he made. His plane is big and bulky. I recommend your first plane to be something similar to Experimental Airlines https://www.youtube.com/user/ExperimentalAirlines/videos . He has a lot of good planes for beginners but I do not like his style of building fuselages. They are weak and flabby. I will post another i'ble hopefully soon on how to make your own beginner RC foam board plane.

Don't forget to check out flitetest. Those guys are simply awesome! flitetest.com

All the parts are from HobbyKing.com So far all of the parts that I've gotten from there are very good quality despite their super low prices. Thanks hobbyking!

Supplies:

Step 1: Transmitters

The transmitter is what you use to control your plane with. This is usually the most expensive electronic component that you will buy.

Most modern transmitters us a 2.4 Ghz frequency. These new ones have shorter antennas and are easier to work with as opposed to the oder FM radios.

The transmitter that I use the HobbyKing's transmitter. It cost 25 dollars for the transmitter AND the receiver. Its probably the cheapest 6 channel radio on the market today. I've been using this transmitter for about a year and a half now and the only downside to it considering it's price is that it eats batteries. You might consider making it run off of a lipo battery.

Speaking of a 6 channels what does that mean? There are 3-,5-,6-channel transmitters and so forth. Channels are the amount of things you can control. For instance a three channel transmitter means you can only control three motors/servos/accessories. A standard RC transmitter you buy for a RC plane has 6 channels. These channels are controlling the rudder, elevator, ailerons, motor, Aux 1, and Aux 2. So basically each channel controls a different motor.

Aux 1 and Aux 2 are reserved for different features on your plane. For instance you could have 2 bomb drops, or 1 bomb drop and a set of lights. The auxiliaries are usually controlled extra switches or knobs on the transmitter.

Step 2: Receivers

The receiver is what goes into your aircraft and controls the servos and motor(s). You can see from this receiver that it is a 6 channel receiver. The BAT slot is not considered a channel. The receiver shown above was only 10 dollars as opposed to around 20.

The receiver above connects wirelessly to the the transmitter using a 2.4Ghz frequency. 2.4Ghz frequency is the standard frequency for RC planes.

The receiver runs off of 5v, and sends signals the the servos to turn them. It also sends a signal to the ESC (we'll talk about that later) to tell it how fast the run the motor.

Now you may be wondering were the receiver gets it's 5 volts from. It gets that from the ESC's BEC, or battery elimination circuit. Keep reading to find out more about the BEC.

The anttenas on these guys like to break, so I suggest covering the part where the antenna meets the receiver wih a bit of hot glue to relieve the strain on the wire.

Make note: Each receiver will only bind with a specific brand and type of transmitter. Make sure you buy a matching pair transmitter/receiver.

Step 3: ESC (Electronic Speed Controller)

ESC basic info

ESC. An Electronic Speed Controller does several things. First, it converts your battery voltage down to 5v which is what your receiver runs off if. Not all speed controllers have this capability. When buying one what you are looking for is and ESC which says on it BEC or UBEC. This stands for [ (Universal) Battery Elimination Circuit.]

The second thing the ESC does is it converts the DC power from your battery to an AC current which is required by the motor. Brushless motors run off of AC current.

Choosing an ESC.

When picking out and ESC there is one very key feature to look out for. That is the amperage rating. Each motor will take a different amount of amps. Say I have a motor that pulls 10 amps. I do not want to buy an ESC that is rated for 10 amps. I would want to get an ESC that is rated for 15 or 18 amps. It is always good to go higher. The higher amp-rated ESC you get the less heat will be radiated.

Speaking of heat, this ESC can get very warm at times! That's why it is important to get a ESC with an amperage rating higher than your motor or your motor will pull too many amps through the ESC and cause the ESC to overheat and possible catch fire.

Then you risk a fire and burning up your RC plane! That would be horrible! Then your plane would go down in flames onto your neighbors hay barn, catch that on fire, then a the fire starts spreading. . . I'm just kidding, well about it burning everything up part :D.

The ESCs should be placed in such a manner that they get sufficient airflow to keep them coo.

Step 4: Battery

Batteries have several different characteristics. LiPo (Lithium Polymer) batteries are standard for the RC hobby.

The first thing to talk about is the battery's voltage. While the batteries exact voltage may not be printed on the battery itself but it will tell how many cells the battery has. LiPo batteries are made up of cells. Each cell is 3.7 volts. for example the battery shown above is a 2s battery. This means that is has 2 cells, which would give it a total voltage of 7.4 volts. These cells fully discharged should NOT go below 3.3 volts and the cells fully charged should not go 4.21 volts. So for a 3S battery fresh off the charger it will be about 12.4 volts. You can drain that battery all the way down to 10.6 volts. The less you drain the battery the better.

The next thing is the Amp capacity. The battery shown above is a 2200 Mah battery. This means the battery can supply 2200 milliamps over a 1-hour period.

Finally there is the discharge rate. This particular battery has a 25c discharge rate. This is how much current the battery is able to supply. The higher the discharge rate, the more power you will get from your battery. In order to see how much current your battery can deliver, multiply the C rating by the capacity of the battery in amps. For instance the battery shown above is a 2.2 amp (2200mAh) battery with a C rating of 25. 25 x 2.2 = 55. This means during it's lifetime 12.6 volts down to 10.6 this battery can constantly supply up 55 amps of current. This is plenty enough to power any foamboard planes.

Step 5: Motor

You motor is the power plant of your plane. The motor will turn your propeller at a high speed to propel it through the air! The standard motor that you put in your RC plane is brushless, which means it runs off of AC current. This is why you need a speed controller to convert the battery's DC power into AC.

When choosing a motor there are two basic things you need to look for.

RPM. The motor above runs at 1400 KV. KV means that for every volt applied motor will spin 1400 times. If we use a 2s battery (7.4v) then our motor's RPM is 10,360 ( 1400Kv x 7.4v = 10,360 rpm).

Power rating. The motor below is 52 watts. In order to find the wattage of the motor multiply the max current of the motor by the voltage applied to it. This motor pulls 7 amps and uses a 2s battery (7.4v) so 7 x 7.4 = 51.8W

This motor is suggested for a 275 gram plane.

Step 6: Servos

Servos are what move your control surfaces. The servos plug into the receiver. The ailerons plug into channel 1 on the receiver and the elevator plugs into channel 2 on your receiver.

Step 7: Soldering

When you get your speed controller it will not have all the connectors necessary to hook everything up so you will need to pull out your soldering iron and heat shrink and get to work! The speed controller hooks up to three things, the motor, the battery, and the receiver. With that in mind. . .

First find out what type of battery connector is on your battery. The type of plug that was on the battery shown above was an XT60 type. This means you will need to buy one male XT60 connector for your ESC. (the two big wires from the ESC connect to the battery)

Make sure when you solder the wires on that they are in the correct polarity. You can 'half plug' the two connectors together and make sure that the red and black wires match. Make sure to cover any exposed wires with heat shrink.

Now you need to add the connectors that go to the motor. On the specifications for your motor it should tell you what type of connetors are on. For instance, the motor shown above comes with 3.5 mm 'bullet' connectors. In order to connect this to the ESC, you will need 3x 3.5mm bullet FEMALE connectors. Solder these three onto the three wires coming out of the ESC. Again, make sure all exposed wires are covered in heat shrink. Now slide the male connectors from the motor to the three female connectors coming from the ESC. Make note, it does not matter which order you plug them in for now. See the last image to see the motor attached to the ESC.

Refer to pictures for further instruction.

Step 8: Connecting It All Up!

Make sure when you connect anything to the receiver that you push in the servo leas so that the brown wire (negative) faces AWAY from the text on the receiver.

Connect the battery and the ESC

ESC servo lead to channel 3 on receiver. You plug this into channel three and NOT the BAT slot. You would plug the battery into the BAT slot if you were making a plane without an motor, i.e. a glider.

ESC to the motor. Connect the three wires in any way. You can change this later.

Step 9: Binding the Receiver to the Transmitter

So now you have everything hooked up, but when you turn on the transmitter, nothing happens! Well this is because you haven't bound the receiver to the transmitter.

Binding the receiver.

When you get the receiver it has to be bound to the transmitter. If your transmitter is not bound to the receiver than you will not be able to control anything. The steps below are for binding this specific receiver, but works with others too. Consult your manual for further instruction.

1. Plug the bind plug into the BAT slot. 2. Plug in the power connector from your ESC. Make sure you have the ESC connected to the motor and the battery. 3. The red light on the receiver should start flashing 4. Turn on your transmitter holding down the bind switch. The bind switch must already be pressed before transmitter power-up. 5. Wait a few second and if you see the red light on the receiver stop flashing then you have successfully bound it!

Step 10: Where to Buy Parts

RC electrons have been continually been getting cheaper. All the electronic shown in this instructable were taken from HobbyKing. Hobbyking is one of the cheapest web sites online. Please visit www.hobbyking.com to check out their incredibly low prices.

Step 11: Conclusion:

I hope this has been helpful to you in understanding what parts need to be connected to what. If you have any question feel free to PM me or to leave a comment! Don't forget to vote!

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208 Discussions

Hi, I am using 2-6S 80A UBEC Brushless ESC With 5V/5A BEC and 6S lipo battery of 5000mah. will it be compatible with (FMS 70mm 12 Blades Ducted Fan EDF With 2845 KV2750 Motor For RC Airplane). I saw some product specific note that,- The motor only support 4S battery,but the ducted fan support 6S battery (need to use other motor).Please suggest if buying this is not wastage of money for me. What is that mean by?

First of all let me congratulate you on a brilliant explanation article.

However, I don't understand why you must turn on the transmitter before attaching the battery. That seems backwards to me as it might be that accidentally the throttle may be turned on and when you connect the battery it will cause the motor to run.

BTW - buy most of my stuff including rx & tx from Hobby King and am just about to add the radio to a Durafly Slow Poke I assembled yesterday.

I understand where you're coming from. So the deal with turning the TX first is that a lot of TX/RX systems require the transmitter be on first before the RX would turn on, so that the binding will happen properly. Most of the remotes I've worked with it doesn't really matter what gets turned on first.

ESCs have a built in protection feature, they won't initialize unless the throttle value is set to minimum. Usually the sequence is beep beep beep (long pause), low beep, high beep. If the throttle is above the minimum threshold, it just goes beep beep beep and stops. Once you return the throttle to low, you'll hear the last two initialization beeps, low beep, high beep.

In fact, to enter ESC calibration, you turn the RX/ESC on with the throttle set all the way to high (with the TX on first of course). Follow your ESC's instructions for calibration.

Good luck with the planes! If you happen to make my trainer plane post up pics!

Thank you.My motor does gives specs about the propeller, current draw, supply voltage, etc but not thrust. And we are making a heavy plane with payload of about 10kgs. So how much Thrust/Weight is sufficient for the plane to fly ?

The answer depends on what you want the plan to the craft do and how aerodymamic it is. For example if it had a glide angle of 10:1 it would need 1kg thrust just to keep it in the air. Then add some more to enable it to climb - say times 2 (at least). If you want to do aerobatics you probably want thrust>weight. My suggestion would be to look for examples of similar aircraft and see what power systems are being used. That should at least get you in the air. You then may well need to make some changes to get the flight charastics you need. Mike

Just check the specifications of the motor before you purchase. If you are buying from a decent website, they will have all the relevant information that you will need for that motor, including recommended prop size, how many grams of thrust it will make with said prop, current draw, supply voltage etc.

Hi, can I PM you about my own questions? I've never done RC but this year me and a group of students built a light sport two seat airplane called an RV-12. Having finished the plane and all of us having flown it, we're preparing to build another one starting in about 2 weeks. I would like help and suggestions in designing and building an RC version of this plane that we could keep and fly even after we sell the real one. Thanks!